Due to the increased influence of electronic communication on the modern life, attacks on secrete data have become to a more and more serious problem. In order to protect against data attacks electronic keys are used. Such a key has to be known until a restricted area within a data storage device becomes accessible for a user e.g. by opening a data connection via a computer network such as the internet.
In order to repeatedly use an electronic key it is known to store such keys on non-volatile memories such as e.g. a read only memory (ROM) or an electrically erasable programmable read only memory (EEPROM). However, hackers frequently attack data storage devices including such memories for gleaning electronic keys. Therefore, it is extremely important to provide an electronic key storage, which has to withstand many invasive and non-invasive hacker attacks.